Topic: 1973 CB350F "Freakshow Build" completed! Stay tuned for updates...

[Tim in Ohio]

Shop manual says apply "liquid packing to the cylinder head cover packing groove.  Install the packing in place."

Question:  "Liquid Packing?"  Huh?  Where do I get this?  does it go by any other names?

Here is the gasket/ "packing" they are talking about:

[hoodellyhoo]

I'm no expert, but I think the gasket is all you need. I put a new one in when I took my valve cover off and it's been just fine.

[HavocTurbo]

Just for reference....

I have always activated RED threadlocker with a quick 30 second blast with a torch. Somewhere in the directions I think it says that.

Every helicoil I have installed (I work at a dealership and sadly we use them a lot) has been heated for that extra security.

You don't NEED to do it. This is just for reference.

PS - +1 on the blue locker for the stud. Makes it a little easier on you should you need it.

[TwoTired]

Question:  "Liquid Packing?"  Huh?  Where do I get this?  does it go by any other names?

liquid packing must be a translation from Japanese.

I expect it's just a gasket sealer or a contact cement that holds the rubber into the cover groove so it won't fall out when you turn it over.

I've always used Gaskacinch for this task.  Put a thin layer in the groove and then a thin coat on one side of the rubber.  Wait for it to dry and mate the two pieces.

Cheers,

[Tim in Ohio]

Two-Tired:  You mention Gaska-cinch.  I saw that mentioned in an article elsewhere on this forum ( http://forums.sohc4.net/index.php?topic=38253.0 ).
It is a posting of an article from a 1981 issue of Motorcyclist Magazine (an interesting read about upgrades for the CB750).  In discussing the installation of the base gasket that the cylinder block will sit on, it says:  "Apply a light coating of Gaska-Cinch or Copper—Coat to the cylinder base gasket and let it dry for about ten minutes. Be sure there is no oil on the surfaces that will be in contact with the gasket. Install the gasket."
I picked this up at Walmart, will it work like Gaska-cinch for both the valve cover "Liquid Packing" application as well as the procedure described above for the cylinder block base gasket?:

[Tim in Ohio]

By the way, in that same article above, the author mentions rubber seals around some of the studs (I added the emphasis - see below).  Could this be a reference to the rubbery bands I keep mentioning thaat are on some of my studs???

STEP 5: HEAD INSTALLATION. Inspect the assembled head for dirt and any remaining gasket material that might have been overlooked. Clean the surface that will come in contact with the head gasket. Similarly, inspect and clean the cylinder itself. Be sure that all locating dowels are in place as well as the rubber seals around the appropriate studs. Smear a thin coating of Yamabond, Kawasakibond. Gaska-Cinch or Copper-Coat onto the head gasket top and bottom surfaces. Place the gasket on the cylinder (watch the orientation) and the head on the gasket. Immediately place the lightly oiled copper washers and nuts on the cylinder studs and torque the head to 19 foot/pounds. It is important that the head be torqued before the gasket cement has set up, and it is important that the washers and nuts be oiled. The specified 19 pounds of torque is higher than the factory recommended value, but their head gaskets leak and yours won't. Let the engine set for about ten hours and torque the head nuts again.

Could he be talking about:



I took mine off.  As you can see they aren't in great shape.


I have seen NO mention of these things in my shop manual or Clymer.  So even if he IS talking about those darn things...  I have no reference information to tell me which are the "appropriate" studs.     

[Spikeybike]

looks like left over hondabond or some kind of sealant , definitely not rubber

not sure about on the 350 but the 550 has no such seals

[Tim in Ohio]

Here is where I left off for the night:
Pistons back on!
   

[mattcb350f]

Hey Tim!!! been away for a bit and missed all the fun. great job so far 

The 'rubber band' stuff is just left over silicone sealer that someone (PO) must have put on there. I see you already have taken it off. Good.

I've never seen that much 'over sealing' on a factory job, which is why I say a PO did it 

When the instructions refer to "...as well as the rubber seals around the appropriate studs..." they are talking about the FOUR (4) rubber sleeves/gaskets/seals (whatever you want to call them) that go around two of the locating dowels on the cylinder head, as well as the oil control orifices. Two larger ones around the dowels, and two smaller ones around the oil control valves.

As far as I can remember, those are the only two rubber gaskets that go between the cylinder and head on this engine, besides the head gasket itself.

Now.. there was mention about studs that have oil around them......As far as I know, the only ones that come in contact with oil are the outside front studs which are part of the oil return from the head. -----Do not silicone these at all!

The outside front studs use the two cylinder head nuts that look like regular nuts. The other ten nuts will be capped........they look like the ones on the upper rear shock mount on the 350F. The capped ones keep the oil away from the threads of the studs which are exposed around the cylinder.


And now, some other tidbits of advise...

Install the base gasket.........trust me. do this soon. I'm not afraid to admit I have forgotten before in the heat of engine building 

Check to make sure that all the rubber cushions which are part of the cam chain tensioner are in place before installing the cylinder (see parts diagram).....its much easier to do this now than later 

Oil the piston rings well and align them before installing the cylinder and if you can, find someone to help with putting the pistons in the cylinders. Also, take your time.......it is easy to break a ring doing this and you won't know until you get it running and have weak compression.

I think that about does it, Except for one thing..... member ttr400 recently outlined his procedure for head gasket installation on the 400F. Since my 350F head is leaking now, I plan to do his procedure this winter.

Have a search or if I can I'll post the link to the thread here. The 350F/400F head can be a leaker but as ttr400 says, he never has leaks when he does it his way...which involves sealer around those 4 rubber gaskets and some copper spray sealant on the head gasket.

 Matt.

[mattcb350f]

GOT IT!

"Is it possible to have a non-leaking CB350F" - http://forums.sohc4.net/index.php?topic=40549.0

...which member Kevin says: "This is what I do with my motors and so far do not have any leaks, these are also race motors so get ridden at the limit and beyond 100% of the time. First after making sure that the cyl head and cyl block surfaces are super flat. I have mine skimmed, or by some of the methods already mentioned. Make sure the surfaces are nice and clean, install new rubber seals on the 2 oil restrictors and on the 2 studs, use a very fine layer of Honda bond around those seals. Spray a new head gasket with head gasket copper coat, allow a couple of Min's before you fit the gasket. Fit the head and torque the nuts as per the workshop manual to 14.5-16.7 lbs-ft. Then I torque to 18 bls-ft. carry on and complete assembly. let it stand for a few days before starting the motor.
This has always worked for me." - Kevin


...like I say, after my leaky head after rebuild, I'm going to do this, this winter.

BTW, Is it friggin' cold in Ohio too. I just bought some long underwear specifically so I can get back on the bike this week without freezing my a$$ off.

 Matt.

[TwoTired]

Two-Tired:  You mention Gaska-cinch.  I saw that mentioned in an article elsewhere on this forum ( http://forums.sohc4.net/index.php?topic=38253.0 ).
It is a posting of an article from a 1981 issue of Motorcyclist Magazine (an interesting read about upgrades for the CB750).  In discussing the installation of the base gasket that the cylinder block will sit on, it says:  "Apply a light coating of Gaska-Cinch or Copper—Coat to the cylinder base gasket and let it dry for about ten minutes. Be sure there is no oil on the surfaces that will be in contact with the gasket. Install the gasket."
I picked this up at Walmart, will it work like Gaska-cinch for both the valve cover "Liquid Packing" application as well as the procedure described above for the cylinder block base gasket?:

I don't like the silicon gasket makers, unless there is no other choice. Too easy to use too much, then little pieces break off and clog up oil orifices, then you have siezed cam bearings etc.

Your question seems similar to asking if diesel fuel can be used in place of gasoline.  They make different kinds of gasket sealers/makers for a reason, and using the right one in the right application has it own benefits.  For the cylinder cover gasket (assuming you have a new one) it should do the job of sealing all on it own, once you get it in place.  The main reason to use a sealer/glue is to fight gravity during installation so it stays in place.  It keep keeps the gasket in the cover groove. Secondarily, it ensures any leaks that occur, happen only at the head to seal surface and not the seal to cover interface.

Cheers,

[Tim in Ohio]

OK I checked Autozone and Advanced Auto Parts, neither had "Gaska-cinch"... 
Is this stuff the same idea?  Will it work for my purpose?
Or to keep Two-Tired's diesel fuel vs gasoline analogy going... have I brought home some jet fuel?   

[Tim in Ohio]

Oh yeah...  forgot the pic:

[scunny]

looks to be the stuff to me Tim. never used it myself but I wouldn't doubt TT and kevin. I might even look for some of that myself since I have to pull my head off again(just to allay a nagging thought)

[Artfrombama]

This is gasgacinch

It's good stuff but I use the copper gasket cement in the dauber can. The aerosol is too messy.

[TwoTired]

That stuff is for head gaskets, (for those that are paranoid) or are using thin metal head gaskets with no fiber content.  See the picture of the head gasket on the front label?

It might work ok for the cylinder cover gasket.  Spray some in a cup and use a small brush to thin coat the cover groove where the gasket goes.  Read the directions.  Does it say to coat both mating surfaces or just one side?

Do a small test to see if it is sticky enough to retain the rubber gasket in the cylinder cover groove.  If so, it will be an ok substitution.

You can use that for the base cylinder gasket, BTW.  It's a spray so DO NOT let overspray into the inards of the engine where ANY oil is flowing.  Glue and contamination of the oil supply is a BAD thing!

Motorcycle shops often carry Gaskacinch.  Did you check your Harley shop?

Cheers,

[Tim in Ohio]

Art thanks for th pic.  I'll get some tomorrow.  I took all of my wrong purchases back to the store(s).

[Tim in Ohio]

What is the best method for getting all of the old gasket off and creating a really clean mating surface.  I assume that one must be careful not to let the debris fall down into the case.

[Tim in Ohio]

OK...  everybody clammed up on me, so I will throw out the first gasket cleaning tips:
I found this advice that FASTBROSHI gave to someone on another post...  sounds pretty good:
"As for tools for scraping the gaskets, you'll have to get creative around the studs and pistons.  Gasket remover is a big help here.  Be careful not to nick the gasket surface up.  Get yourself a bunch of razorblades and a good gasket scraper with the screwdriver type handle and go to town."
 

[kghost]

Hey sorry Tim.

I like a piece of plexiglass. I'm fat fingered and I've knicked stuff with a razor.

A brass brush helps. SO does a little MEK or Acetone with a brush...to loosen up the really glued on stuff.

[mattcb350f]

Ok, gasket surface cleaning tips eh'

Razors and your choice of softening fluid. I use WD-40, which helps soften glue/silicone.

Avoid sandpaper to get stuborne stuff. Instead, use scotchbrite pads. Sand paper will do a lot of harm to the surface and while scotchbrite pads can do damage if you use it in one spot for a long time, they are less likely to hurt the surfaces.

Razors will do most of the job but be carefull with the razors which can easily bite into the aluminium........and you fingers 

If the head was 'surfaced' or 'skimmed' than don't touch it. If not than I suggest either getting it done or follow some other suggestions about how to do it yourself. I have done small (single cylinder) cylinder heads with a thick plate of glass and some 400 grit, and 800 grit sandpaper but have never done a multi-cylinder head myself.

TwoTired's points about using sealer on the cam cover gasket to hold it in place was spot on (as usual  ). The first time I used a new gasket here it stayed in place just fine.........the second time I used a little sealer to hold it there and got a second use out of the same gasket.
I also agree with being carefull with the sealer... I've seen a few engines with clogged oil galleries from over-siliconization

...and on that note, check the oil manifolds that go in the head which squirt oil at the camshaft. They have tiny holes which need to be clear before assembly.

 Matt.

[Tim in Ohio]

OK Guys.  Matt has brought me to a place of motorcycle enlightenment. 

I realize that slapping this engine back together in a hurry so I can ride it for the next couple of days or weeks of remaining decent weather, is probably not a great long term gameplan.   So, I am going to back off of the hurrying and do it right.  Maybe I'll get a little riding in before Winter sets in... maybe not.  Either way, if I build it right...  I am hoping for trouble free performance for a (reasonably) long time.

So, that said...  I intend to follow up on Mattcb350f's last post and obtain the supplies, tools and knowledge to 'surface' or 'skim' the head before I go ahead and bolt it back on.
Anybody who can steer me on that, please reply with advice, links or even a full blown step-by-step "How-to: Surface a head" post on this thread.    You realize that by contributing info like that you will be going down in history.  Because this thread is going to be the definitive text on "How to Restore a CB350F Even if You are a Complete Buffoon."   Noobs will be referencing this thread and quoting your techniques for years to come...  so if you have some knowledge, speak up!   

[Artfrombama]

OK Guys.  Matt has brought me to a place of motorcycle enlightenment. 

I realize that slapping this engine back together in a hurry so I can ride it for the next couple of days or weeks of remaining decent weather, is probably not a great long term gameplan.   So, I am going to back off of the hurrying and do it right.  Maybe I'll get a little riding in before Winter sets in... maybe not.  Either way, if I build it right...  I am hoping for trouble free performance for a (reasonably) long time.

So, that said...  I intend to follow up on Mattcb350f's last post and obtain the supplies, tools and knowledge to 'surface' or 'skim' the head before I go ahead and bolt it back on.
Anybody who can steer me on that, please reply with advice, links or even a full blown step-by-step "How-to: Surface a head" post on this thread.    You realize that by contributing info like that you will be going down in history.  Because this thread is going to be the definitive text on "How to Restore a CB350F Even if You are a Complete Buffoon."   Noobs will be referencing this thread and quoting your techniques for years to come...  so if you have some knowledge, speak up!   

Most automotive machine shops can surface your head...
To get a good sealing surface for the head gasket you can use a sanding block and a sheet of 80# paper.

[mattcb350f]

Looking at this pic it doesn't look like the head has been surfaced, but it does look like somebody cleaned it up (swirl marks which look like scotchbrite or high # sandpaper). However, it is possible that the machine shop checked the surface for warpage and it was within limits and they decided not to do it.

First off Tim, I would get in touch with the shop that performed the work and ask them if they checked it. If they did and said it was ok, then I suppose it may need just a cleaning up.

When my machinist surfaced my head, he actually pressed it straight with press and just dressed it with the surfacing machine to give it a nice surface. Because of the narrow point in the middle of the head where the cam chain goes through, they tend to 'warp' at this point. However, in pressing the head straight, this also changes the cam bearing surfaces as well as the cam cover surface so there was a lot of measuring involved to make sure that everything cam up true.

I suggest that you get a shop to surface the head if needed, but if the machine shop that you have already used has checked it and found it to be ok, then clean it up with the glass and sandpaper trick.

 Matt.

[kghost]

+1 on the Glass and sandpaper trick.

Purpose of the glass is to get an absolutely flat surface.

Couple passes with the sandpaper between the glass and the head will tell you how flat that head is.

I believe your on the right track with slowing down. I never seem to get good results when I rush or hurry.